The invention relates to commercial coffee brewing systems and is particularly directed to improving upon systems that include a central brewing unit which siphons hot water from a hot water tank to a coffee brewing chamber and then discharges brewed coffee into a transportable satellite receptacle unit arranged therebelow and adapted for receiving, storing and dispensing the hot coffee. The invention specifically fills the needs of the so-called fast food industry by providing a high volume coffee brewing system for making quick, successive batches of high quality coffee and which utilizes interchangeable and portable satellite receptacle units that permit serving the coffee either at the central brewing unit or at remote service stations in a restaurant.
In the food service industry, the prompt availability of good quality coffee is a major concern. Since customers may request this beverage in sporadic intervals and varying amounts during the course of a day, it has become necessary to have fresh, large volumes of coffee available on a continuing basis. Thus, a high volume brewing system has been sought which can brew and make available a substantial amount of coffee in a short time with little supervision required by the restaurant employees. A major problem with present commercial systems is that the recovery time required to re-heat hot water for a next brew is too slow to effectively meet the demand at peak business hours. High wattage heating elements have been tried, but the increased wattage presents a problem due to the overheating of conventional switching and thermostat components in the electrical system. Another problem discovered is the inherent inability of brewed coffee to retain its fresh taste for longer than about thirty minutes while being heated inside a dispensing receptacle to maintain the required hot serving temperature. Past this point, brewed coffee degrades and is rendered unpalatable. The maintenance of high quality standards is a great concern to the operators of restaurants who have developed significant repute and goodwill due to their diligence in serving fine quality food and drink. It would accordingly be desirable to avoid this heat degradation by eliminating the need for heating the coffee after it has been brewed. It would be a further advantage to provide a quality control system that monitors the age of a batch of coffee whereby the operator can easily determine when the coffee has reached a less-than-desired serving temperature and thereby discard an old batch of coffee rather than inadvertently serving it.
The demand for a constant supply of fresh coffee has not been met by the use of urn-type brewers. While large volumes of coffee can be brewed in such systems, the coffee is required to be stored in the urn and maintained at the proper temperature. Unless all the coffee is served, the remainder should be discarded upon reaching the point of degradation. Thus, not only does the restaurant operator lose the potential sales for this coffee, but a long time delay is experienced while the next batch of coffee is brewed in the urn. A siphon-type brewing system which allows the restaurant operator the option of having several receptacles of hot fresh coffee available and the means for quickly brewing additional batches to replenish empty containers would greatly enhance restaurant efficiency and avoid the wastefulness connected with urn-type devices.
Additionally, a siphon-type system which provides satellite style receptacles that do not require continuous heating and may be stationed remote from the central brewer while another satellite is being filled would further advance commercial brewing techniques.
In ascertaining the goals of the food service industry, it has been learned that it is preferable to utilize a single spray head and brew chamber arrangement, wherein the single brew chamber is adjustable for the alternate filling of satellite units positioned in at least two orientations adjacent the central brewer. Only one siphon tube and spray head arrangement would be needed to convey hot water from the tank. This capability would eliminate the need for multiple brew chambers, streamline coffee making effort in a restaurant and also result in the minimization of components and size of the brewing device.
A safety switch arrangement that prevents the brewing of coffee unless the adjustable brew chamber is properly positioned would be a great advantage to assure that a brew cycle is not initiated until the brew chamber is correctly oriented for discharge into a satellite receptacle aligned for filling therebelow.
In brewing large volumes of coffee, such as one to two gallons (7.57 liters) per cycle, it has been discovered that the coffee grounds can be overextracted and the resultant coffee is bitter. Accordingly, the need has arisen for the by-passing of a percentage of the hot water around the coffee grounds and directly into the receiving receptacle. In this manner, all of the hot water does not immerse the coffee grounds and overextraction is prevented. When softened water is used, much less is required to be directed though the grounds for proper extraction than with the use of untreated, or hard, water. As water conditions, as well as the coffee blends, vary it will be understood that the amount of water needed to correctly brew the coffee will also vary, and therefore the capability of adjusting the percentage of by-pass water would be very useful. A related obstacle to achieving a by-pass system for large volume brewing involves the filter paper which retains the coffee grounds in the brew chamber. The filter must be positioned so that the by-pass flow is not restricted by the paper to be inadvertently passed through the grounds. The by-pass water must be effectively directed around the filter paper and grounds so that it quickly flows downward to the discharge orifice and into the receptacle. It will be appreciated that an adjustable by-pass system that achieves these goals, in combination with a single spray head and adjustable brew chamber assembly, would significantly advance coffee brewing techniques.
In the past, warming plates have been required to maintain the temperature of the brewed coffee held in a receptacle. The elimination of warming plate devices and the attendant electrical costs for energizing their heating elements, would offer both a monetary saving and reduction in the size of the system. A satellite receptacle unit that functions as a thermos-type bottle to maintain brewed coffee "fresh" and at a desired serving temperature of from about 170.degree. F. (76.7.degree. C.) to about 180.degree. F. (82.2.degree. C.) for a one hour holding period and which thereby eliminates heat degradation, additional electric costs and warming plate structures, would be valuable advances in the art.
It is also an object of the invention to ensure that the coffee is dispensed from the satellite receptacle at the desired serving temperature. This has been a particular concern when a conventional sight glass, or sight gauge, is combined with the satellite receptacle for the purpose of observing the volume of coffee remaining therein. It is, of course, important that the volume of coffee be monitored in this way so that the restaurant operator can determine when it is time to re-fill a unit. The sight glass is required to fluidly communicate with the interior of the receptacle upstream of the dispensing spigot whereby the coffee flows into the sight tube and reaches the corresponding fluid level found in the receptacle. Because the sight glass is located outside of the container, it is surrounded by the cooler ambient air conditions. A sufficient amount of coffee may be held in the sight glass to fill a cup of coffee. When the dispensing spigot is opened, the coffee in the tube will seek to flow downwardly through the spigot and into the coffee cup. As a result, cooler coffee, much below the desired drinking temperature, could be found in the cup of coffee served to the customer. It would be advantageous to greatly restrict the amount of coffee that flows outwardly from the sight gauge when the dispensing spigot is open, but still allow for the fluid communication with the coffee inside the receptacle to permit monitoring the level therein.
While the primary objective is to achieve an improved large volume brewing system, it will also be appreciated that the satellite coffee brewing system should include the ability to brew smaller amounts of coffee. A related object would also be the ability to precisely adjust the volume of cold water admitted to the hot water tank in response to changing water line pressures so that a uniform volume of brewed coffee per cycle is maintained. In known siphon-type brewing arrangements, a timed inlet valve controls the amount of cold inlet water admitted at the bottom of the hot water container which in turn displaces an equal amount of hot water to be siphoned from the top portion of the container for brewing. Should the required amount of coffee to be brewed, or the inlet pressure change, it would be very helpful to precisely adjust the open-time of the inlet valve whereby the exact desired amount of hot brewing water is siphoned from the tank. In the past, manual adjustment of the timer for the inlet valve was made possible but the adjustment was imprecise and often resulted in admitting too much water or too little water. Thus, inefficient trial and error experimentation at different settings was needed.
With particular regard to the efficient service procedures required in fast food-type restaurants, it will be understood that space-saving devices are demanded. Typically these establishments serve a wide variety of food and beverages, and the convenient accessibility of the various cooking and dispensing devices is critical to providing the prompt service expected by the customer. A satellite coffee brewing system must therefore not only meet the goal of brewing good tasting coffee, but should also be designed so that the system does not contravene the spacing requirements for other serving and cooking devices. It has been learned that the width of coffee making units is the single most critical design feature due to the typical side-by-side arrangement of coffee brewing units with other devices typically found in a restaurant. The more cooking and dispensing devices that can be usefully positioned in close proximity near the customer service counter, the greater the efficiency of the restaurant operation. A satellite coffee brewing system that provides a brewing unit capable of being arranged with at least two satellite units thereat to achieve an overall width of less than sixteen inches (40.6 cm) would meet the most rigid standards of the industry.
For sanitary reasons, the design of such a brewing system must also allow restaurant personnel to clean beneath the brewing units. Standard health codes and regulations dictate that coffee making devices provide for a four-inch (10.2 cm.) vertical spacing above the work counter in order to permit regular effective cleaning to be made. These practical concerns for size and spacing must be considered in conjunction with the operational requirements for quantity and quality brewing.
In summary, the invention may be described as a compact high-efficiency satellite coffee brewing system which comprises a central coffee brewing unit cooperative with a plurality of interchangeable, thermos-type satellite containers and offers the capability or large volume, almost continuous, brewing and the ability to keep brewed batches fresh and hot for serving from the satellite units either while they are stationed at the central brewing unit or when moved to remote sites in a restaurant. The brewing unit is capable of sequentially filling at least two satellite units arranged therewith. The central brewing unit includes a housing having a hot water tank heated by an electrically energized, and thermostatically controlled, heating element wherein the hot brewing water in the tank is displaced and siphoned to a brew chamber upon opening a water inlet valve assembly when a brewing cycle is initiated. The housing further includes mounting means for removably holding an adjustable brew chamber beneath a single spray head assembly which directs hot brewing water from the siphon into the brew chamber. The system provides significant improvements in the art including a high capacity heater for the "quick recovery" of the necessary brewing water temperature following a brewing cycle. The system is adapted to accomodate a heating element of substantially greater capacity than the 3600 to 4800 watt range used in conventional systems. A relay arrangement is provided to operate the heater with a 220-240 volt circuit while the running and safety thermostats that control the heater may be operated at the standard conventional 110-120 volt power to prevent over-heating. Further, the central brewing unit includes an adjustable metering valve arranged along the siphon for by-passing clear hot water whereby the coffee grounds are prevented from being overextracted. The brew chamber wall is stepped and is cooperative with a filter paper holding means adapted to engage the brew chamber and ensure that the by-pass water flows around the filter paper rather than being directed through the grounds. The brew chamber further includes a filter spacing means which creases a top portion of the filter paper inwardly from the side of the brew chamber for the receipt of the by-pass water discharged from the adjustable metering valve.
In furtherance of the goals set forth, the adjustable brewing chamber is cooperative with the single siphon, spray-head and metering by-pass valve in any of at least two alternate discharging positions. The satellite receptacles are capable of being interchangeably arranged at any said discharge orientation to facilitate alternate filling thereof.
In alliance with the adjustable brew-chamber, a brew switch and safety switch arrangement is provided to ensure that the brew chamber is in the proper discharge position before a brew cycle can occur.
The unique safety brewing feature comprises, in preferred form, a microswitch positioned at each discharge position wherein a brew switch is wired in series with the microswitch for each location so that a brew cycle cannot be initiated unless the corresponding microswitch is closed. The adjustable brew chamber has switch actuator means arranged thereon to contact and close the microswitch at each discharge position. Alignment means are provided on the brewing unit whereby the brew chamber is positioned thereat to properly locate the switch actuator means for contact with a microswitch and to correctly dispose the discharge orifice of the brew chamber above an inlet to a satellite unit. Thus, until the adjustable brew chamber is positioned in the proper orientation, the corresponding brew switch for that discharge position is not operable and a brewing cycle cannot be initiated. This prevents the inadvertent discharge of hot coffee from the brew chamber.
The invention also provides a timing circuit means and signal light means for monitoring a batch of brewed coffee so that the restaurant operator is alerted at the time when the coffee has reached the point of about 40-60 minutes after brewing.
The brewing system also includes an extender means for a hot water faucet assembly which disposes a discharge end thereat at a convenient height to allow restaurant employees to easily monitor the hot water dispensed into a cup for making tea, or the like. The extender means is flexible to allow for accidental bumping contact and also insulates an inner extender tube wherby the employee's hands are prevented from coming into contact with the hot inner extender tube.
A great advance in the art is obtained because the satellite units are interchangeable for alternate positioning at the central brewing unit. The satellite units have an insulated housing in which a large, preferably seven quart (6.62 liters), coffee reservior is arranged and which keeps the coffee hot for at least one hour without requiring external heating.
The satellite receptacle units are also provided with a dispensing spigot means fluidly associated with a durable sight gauge. The gauges fluidly communicate with the coffee inside the receptacle through a unique restrictor means whereby the outward flow from the tube is minimized so that the relatively cooler coffee held in the gauge does not discharge when the dispensing spigot is opened. Thus, hot coffee is assured to be drawn from the reservoir of the satellite receptacle.
The satellite units also include removable and insulated covers having funnel-type inlet means which may be closely arranged below the discharge orifice of the brew chamber so that hot coffee is immediately directed interiorly of the receptacle and into the insulated reservoir. Each cover is adjustable into a plurality of receiving positions whereby each satellite unit may be placed at every brew chamber discharging position. Positioning and locking means for the cover facilitate the exact secure positioning of the cover in each desired inlet arrangement. Accordingly, the interchangeability of the satellite units makes possible the transport of a filled satellite from the central brewing unit to a remote service station in the restaurant while an empty satellite unit maybe exchanged at the same position for the next brewing cycle.
In the event that a change in the amount of hot brewing water siphoned to the brew chamber is required, means for precisely adjusting the timed inlet valve is associated with the valve timer. The adjustment means comprises a calibrated dial and indicator knob arranged with an adjustment stem of the timer whereby the restaurant operator may precisely adjust the open time of the inlet valve and thereby precisely vary the amount of hot water siphoned into the brew chamber.
The satellite coffee brewing system further achieves an efficient compact space-saving design wherein a plurality of satellite receptacles may be arranged at the brewing unit for the receipt of hot coffee. In preferred form, two satellite units are arrangeable at the brewing unit and provide a relatively narrow width of less than sixteen inches (40.6 cm.) whereby a critical space saving is obtained. No connection between the satellite units and brewing unit is required and the satellites are free-standing and fully portable.
For the achievement of sanitation and cleaning goals, the central brewing unit is mountable on leg means whereby it is spaced from the work counter at the usually prescribed elevation of about four inches (10.2 cm.). The unique design of the system allows for the central brewing unit to be constructed whereby this goal can be met and yet the brewing unit is arranged at a convenient height for the restaurant employees. Because the satellite units are transportable, they do not have to meet the sanitary spacing requirement but may be constructed to also have leg means to space the bottom of the units above cooler resting surfaces. The satellite units are also cooperative with removable drain plates capable of being positioned under the dispensing spigot in order to catch and hold any spilled coffee that might result when a cup is being filled.